1. Field of the Invention
The present invention relates to a representative color value designating method for an image search system, and in particular to a method for designating a representative color of an image region by expressing a representative color value with respect to an image region together with a reliability which represents an accuracy of the representative color, and to a method for measuring a similarity of more than two images and a method for segmenting an image into similar regions using a feature of a representative color value expressed together with the reliability.
2. Description of the Background Art
In an image search technique, a color information used for an image search is an important factor in the characteristic of images.
In a conventional art, there is a method in which an image is segmented into a n×m number of grids, and a color histogram is obtained with respect to each segmented cell, and a maximum value of the thusly obtained color histogram is determined as a representative color value with respect to a corresponding cell. In another method, an average value of the color histogram is determined as a representative color value of a corresponding cell. In another method, a major color vector is obtained and determined as a representative color value for a corresponding cell.
However, since the characteristics of the images are various, it is difficult to express an image using a color in an image region or one color value. It is improper to express a feature of an image by expressing the image region using one representative color value information. In this case, it is difficult to form an accurate database using the characteristics of images, and the performance of an image search using the thusly formed database is decreased. Furthermore, when expressing a representative color of an image region using various colors instead of one color, a large storing space is required. In addition, it is difficult to accurately express an interrelationship between various colors. Therefore, a representative color value of the thusly determined image region has a low accuracy.